Wireless communications systems are known. In those known systems, radio coverage is provided to user equipment, for example, mobile telephones, by geographical area. An access node, for example, a base station, is located in each geographical area to provide the required radio coverage. User equipment in the area served by a base station receives information from the base station and transmits information and data to the base station.
Information and data transmitted by base stations to user equipment occurs on channels of radio carriers known as downlink carriers. Information and data transmitted by user equipment to base stations occurs on channels of radio carriers known as uplink carriers.
In known single carrier wireless telecommunications systems, user equipment can move between geographical base station coverage areas. Mobility Management Entity (MME) acts as a key control node. The MME is responsible for authenticating user equipment and also operates to select a serving gateway for user equipment and a packet gateway. Those gateways may be of use when user equipment initially attaches to the communications network and when user equipment has data traffic to send to the network. The mobility management entity is also operable to reselect serving gateways at times of handover between base stations.
There are various radio states in which user equipment may operate in a telecommunications network. Once it has synchronised and fully attached to a base station it gains a Radio Resource Control (RRC) connection and is referred to as being in connected mode. User equipment in idle mode does not have an RRC connection.
When an LTE or 4G network is overloaded it is operable to reject fresh RRC connection attempts from user equipment. A base station, for example, e Node B, may also be operable to try and relieve an overloaded network by initiating access class barring. In both cases, user equipment which is camped on within a current cell remains camped on within that cell and is not operable to reselect a different carrier or Radio Access Technology (RAT), even if an alternative carrier or RAT available to it is less loaded.
It is desired to improve the load balancing in an overloaded wireless telecommunications network.